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This paper will deal with a variety of topics such as dangers and opportunities from the developing crisis in health care costs, a cooperative study of the cost-effectiveness of treatments for headaches, the need for a federation of related societies, exploiting remarkable electronic advances, the wide range of adaptive functions of visceral learning (including its role in homeostasis), why maladjustments occur and their implications for biofeedback, and the need for analytic experiments involving adequate amounts of training.  相似文献   

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This paper will deal with a variety of topics such as dangers and opportunities from the developing crisis in health care costs, a cooperative study of the cost-effectiveness of treatments for headaches, the need for a federation of related societies, exploiting remarkable electronic advances, the wide range of adaptive functions of visceral learning (including its role in homeostasis), why maladjustments occur and their implications for biofeedback, and the need for analytic experiments involving adequate amounts of training.Presidential address presented at the meetings of the Biofeedback Society of America, April 14, 1985, New Orleans.  相似文献   

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Abstract  The prioritisation of potential agents on the basis of likely efficacy is an important step in biological control because it can increase the probability of a successful biocontrol program, and reduce risks and costs. In this introductory paper we define success in biological control, review how agent selection has been approached historically, and outline the approach to agent selection that underpins the structure of this special issue on agent selection. Developing criteria by which to judge the success of a biocontrol agent (or program) provides the basis for agent selection decisions. Criteria will depend on the weed, on the ecological and management context in which that weed occurs, and on the negative impacts that biocontrol is seeking to redress. Predicting which potential agents are most likely to be successful poses enormous scientific challenges. 'Rules of thumb', 'scoring systems' and various conceptual and quantitative modelling approaches have been proposed to aid agent selection. However, most attempts have met with limited success due to the diversity and complexity of the systems in question. This special issue presents a series of papers that deconstruct the question of agent choice with the aim of progressively improving the success rate of biological control. Specifically they ask: (i) what potential agents are available and what should we know about them? (ii) what type, timing and degree of damage is required to achieve success? and (iii) which potential agent will reach the necessary density, at the right time, to exert the required damage in the target environment?  相似文献   

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A quantum-theoretic picture of the transfer of genetic information is described. The advantage of such an approach is that a number of genetic effects appear to be explicable on the basis of general microphysical laws, independent of any specific model (such as DNA-protein coding) for the transmission of genetic information. It is assumed that the genetic information is carried by a family of numerical observables belonging to a specific microphysical system; it is shown that a single observable is theoretically sufficient to carry this information. The various types of structure that this observable can possess are then described in detail, and the possible genetic effects which can airse from each such structure are discussed. For example, it is shown how the assumption that the genetic observable possesses degenerate eigenvalues may lead to a theory of allelism. To keep the treatment self-contained, the basic quantum-theoretical principles to be used are discussed in some detail. Finally, the relation of the present approach to current biochemical ideas and to earlier quantum-theoretic treatments of genetic systems is discussed.  相似文献   

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R. A. Bear  G. A. Neil 《CMAJ》1983,128(10):1171-1174
The clinical approach to hyponatremia described in this paper involves identification of the hyponatremia as iso-osmolar (factitious), hyperosmolar (mediated by osmotically induced flux of water from cells) or hypo-osmolar. Hypo-osmolar hyponatremia results from decreased renal excretion of dilute urine. This may be caused by renal failure through decreased delivery of filtrate to or function of the ascending limb of the loop of Henle, where dilute urine is made, or through increased water reabsorption in the collecting duct, either independent of antidiuretic hormone or related to a physiologic, drug-induced or pathologic increase in the bioactivity of antidiuretic hormone. The treatment of hyponatremia must be individualized.  相似文献   

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C Berkelhammer  R A Bear 《CMAJ》1985,132(4):360-368
Magnesium plays a critical role in many cell functions. Hypomagnesemia may occur because of decreased intake or absorption, internal redistribution or increased loss of this element through either renal or nonrenal routes. Manifestations of magnesium deficiency include alterations in calcium, phosphate and potassium homeostasis along with cardiac disorders such as malignant ventricular arrhythmias refractory to conventional therapy, enhanced sensitivity to digoxin and, possibly, coronary artery vasospasm and sudden death. Other features of magnesium deficiency include a host of neuromuscular and neuropsychiatric disorders. In this review we detail mechanisms that may lead to magnesium deficiency, summarize the clinical features of the deficiency and provide a clinical approach to the diagnosis and treatment of this electrolyte disorder.  相似文献   

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A Bayesian approach to some outlier problems   总被引:3,自引:0,他引:3  
BOX  G. E. P.; TIAO  G. C. 《Biometrika》1968,55(1):119-129
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This paper launches concepts instrumental to environmental impact assessment (EIA) studies on hydropower schemes and lake regulations. Norwegian hydro-electric lakes (hydrolakes) and their environmental features are described, and evaluated against non-manipulated waters. A tentative classification of hydrolakes vs. natural waters is proposed. The need for a multiple approach to habitat classification is emphasized. Recommendations for future biological impact assessment approaches are suggested.Hydrolakes differ broadly from natural lakes by combining physical features not ordinarily co-occurring in non-manipulated water bodies. Storage type hydrolakes (reservoirs) feature winter draw-downs and enhancement of yearly level fluctuations; whereas other types of hydro-electric lakes have elevated water levels throughout winter. Hydrochemistry and optics of the studied hydrolakes exhibited no clear differences to non-impacted Norwegian inland waters. All lakes had signs of sublacustrine erosional activity related to internal waves and thermocline movements.  相似文献   

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R. A. Bear  G. A. Neil 《CMAJ》1983,129(1):28-31
A clinical approach to potassium imbalances is presented. Hypokalemia is rarely due solely to a reduced intake of potassium; instead, it usually results from a potassium flux into the cells or increased loss of the element, at times combined with a decreased intake. The clinician must seek the cause of the intracellular flux or the source of the gastrointestinal or renal loss. The causes of gastrointestinal losses are generally self evident. Renal potassium wasting, though, generally results from increased mineralocorticoid activity, an increased rate of urinary flow or of sodium delivery to the distal nephron, or both, hypomagnesemia or a combination of these factors. Hyperkalemia may be factitious, but usually it is caused by a flux of potassium from the cells or a decrease in the renal loss of potassium, the latter being mediated by a reduction in renal function, mineralocorticoid activity, or the rate of urinary flow or sodium delivery, or both. In both hypokalemia and hyperkalemia, treatment must be guided by the specific clinical circumstances.  相似文献   

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Current numerical methods for assessing the statistical significance of local alignments with gaps are time consuming. Analytical solutions thus far have been limited to specific cases. Here, we present a new line of attack to the problem of statistical significance assessment.We combine this new approach with known properties of the dynamics of the global alignment algorithm and high performance numerical techniques and present a novel method for assessing significance of gaps within practical time scales. The results and performance of these new methods test very well against tried methods with drastically less effort.  相似文献   

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